Increasing atmospheric greenhouse gases have caused global warming, resulting in considerable shifts in ecosystem function and structure, particularly in sensitive cold climates like the Arctic. As the Arctic continues to warm, the ground thaws and permafrost degrades, resulting in changes to shrub communities. These changes can cause northern tundra soils, which have twice as much below ground carbon (C) as atmospheric carbon, to shift from sinks to sources of C. The fate of this large C pool may be driven not only by climatic conditions, but also by ecosystem changes brought about by arctic animal populations. For example, grazing, burrowing, and defecating are expected to alter nutrients and soil decomposition, although this area of research has not been well explored. In this project I will quantify the effects of arctic ground squirrels, Urocitellus parryii, activity on soil respiration and other characteristics in interior Alaska